SAN FRANCISCO — Fears of getting infected with the coronavirus have prompted authorities in Northern California to allow some sexual assault victims to collect evidence with a nurse directing them in the hourslong process through a video call.

The temporary measure put in place in Marin County after shelter-in-place orders were issued last month to stop the spread of the virus raises issues of evidence contamination and other problems that would be challenged in court, defense attorneys said.

Monterey County Deputy District Attorney Lana Nassoura said Thursday the temporary measure doesn’t apply to victims of sexual assault who are children or who have been injured and is allowed when the victim is comfortable and able to conduct the forensic examination on themselves.

“The last thing we want is a victim not reporting the assault to law enforcement because they’re worried about getting sick, so we wanted to give them an option to be able to do that without those concerns,” Nassoura said.

She said the measure also aims to protect the nurses who normally conduct the prolonged examinations in small rooms and who lack the proper equipment to protect them from exposure to the virus.

So far two sexual assault victims have collected the evidence in their cases, one on April 5 and the other one Monday, Nassoura said.

In one of the cases, the victim was exhibiting COVID-19 symptoms. The victim hadn’t yet received results from their coronavirus test, and officials offered the victim the virtual self-examination to protect personnel.

The examination was done through a Zoom video call “because of concerns that the victim might be infected and to not postpone the examination because it’s best to collect evidence as close in time to the assault as possible,” Nossoura said.

Nossoura said the “temporary protocol” starts when a police officer drops off a rape test kit outside the victim’s residence and then waits in his patrol car. Once the victim retrieves the kit and goes inside, they both join a Zoom video call along with a forensic nurse and a victim advocate.

As it’s done during a normal examination, the nurse interviews the victim and after the officer takes the victim’s statement, the officer and the advocate leave the call. The nurse then directs the victim on how and what evidence to collect.

After the victim places the kit outside their door, the officer collects it and takes it to a forensic lab for analysis. The nurse then offers the victim to do a video call with just the victim advocate, who can offer counseling.

The way the evidence is collected could lead to cross-contamination and would raise reasonable doubt, criminal defense attorney Mark Reichel said.

“It is absolutely fraught with danger because when you have a dispassionate law enforcement officer collecting evidence and replace that with the victim who then manufactures the most critical evidence, that’s going to cause reasonable doubt,” Reichel said.